Clinical images are essential to both the delivery of health-care services and the education of health-care providers. Increasingly, digital images are available online. However, electronically sharing information about images and indexing them to facilitate retrieval of clinically relevant data, pose challenging information management problems. The long-term objective of this proposal is to develop a generalized approach to annotating images with relevant clinical and anatomic information, organized to facilitate the clinical use of those images. To realize this goal a set of tools will be developed to create, store, retrieve, and distribute online annotated clinical images, incorporating structured annotations based on an anatomic knowledge base. The annotation scheme will be developed in collaboration with pathologists, anatomists, clinicians, and other image consumers. It will then be validated in the domain of radiology through development of an example clinical education/clinical reference application, which will include annotated anatomic and pathologic images. A generalized, domain-independent image annotation scheme may be useful beyond medical education, with applications in clinical information interchange, telemedicine, and direct patient care.